Head lamp and lens construction



Jan. 3, 1939.

4 Sheets-Sheet 1 Filed NOV. 27, 1955 Kl f F. f AI I III MII I Ii i III IJan. 3, 1939. cjE. GODL'EY' 2,142,964

HEAD LAMP AND LENS CONSTRUCTION Filed Nov. 27, 1935 4 Sheets-Sheet 2Jan. 3,` 1939. c. E. GODLEY .I HEAD LAMP AND LENS CONSTRUCTION FiledNov'. 27, Sheets-Sheec 3 F E111 7; gramm A C/fa//cs E VGad/eym Wb/@mimiSumma Jan. 3, 1939. c. E. GoDLEY HEAD LAMP AND LENS CONSTRUCTION f FiledNov. 27, 1955 4 Sheets-Sheet 4 @MMM/WS Patented Jan. 3, 1939 UNI TE D rSTAT E S PATENT OFFICE Charles E. Godley, Ferndale, Mich., assignor toUnited Lens Corporation, Detroit, Mich., a corporation of DelawareApplication November 27, 1935, Serial No. 51,868

8 Claims.

This .invention relates to light projecting apparatus and has particularapplication to headlamps usable for automotive vehicles.

The invention comprehends a novel combination of lens, reflector andsource of illumination cooperating to produce a new and improved form oflight projection.

One of the objects of the invention resides in a lens constructionhaving novel means to control-the -rays emanating from a source oflight.

Ihe invention includes a light projecting apparatus rincluding aplurality of juxtaposed zones arranged to direct light in variantinclined directions, and having transition surfaces connecting` sai-dzones, said transition surfaces being arranged to project light rayslaterally.

The invention also embraces a transparent cover or lens constructionprovided with a plurality of prismatic zones for controlling thedirection of the light rays, in having ribs for spreading thelightpassing therethrough in combination with means for avoidingobjectionable glare produced by the formation of said prisms and ribs.

Another object of the invention resides in the provision in a headlampcover or lens having a plurality of spaced prisms of proper angle withone of the faces of the lens in combinationwith a plurality oftransition surfaces of proper light projecting characteristicsconnecting said spaced prisms for directing light rays laterally.

A further object of the invention includes a lens having a plurality ofspaced transverse prisms formed on one face of said lens constitutingspaced zones having superimposed on the inclined surface a plurality ofvertical flutes or cylindrical members in Vcombination with a pluralityof curved surfaces located at the base of the transverse prisms thesesurfaces having substantially the same Ycurvature as that of thevertical flutes.

'I'he invention also includes as an object a novel combination of lens,main reflector, source of illumination in association with asupplementary reflector all cooperating to produce a new and improvedform of light projection where light rays produced by the source arereflected by the surface of the main reflector.

Still another object of the invention is the provision in an automobileheadlamp of a supplementary reflector so positioned with respect to thesource of light and of such proportioned size with respect to the mainreflector that the light rays produced by the source are controlled bythe surface of the main reflector,

(Cl. 24W-441.4)

Another object of the invention resides in a lens construction havingone of its surfaces smooth and the other surface formed with a pluralityof prismatic zones in combination with vertical flutes of apredetermined curvature for 5 directing the rays of light passingtherethrough to one side of the central region of the lens. The lensalso having means located at the base portion of the prismatic zone foravoiding the projection of concentrated objectionable light. 10

Further objects and advantages are Within the scope of this inventionsuch as relate to the arrangement, operation and function of the relatedelements of the structure, to various details of construction and tocombinations of parts, ele- 15 ments per se, and to economies ofmanufacture and numerous other features as will be apparent from aconsideration of the specification and drawings of a form of theinvention, which may be preferred, in which: 20

Figure 1 is a front view of an automobile headlamp incorporating theinvention;

Figure 2 is a side View of the headlamp with certain portions brokenaway;

Figure 3 is an enlarged cross-sectional view of 25 a lens embodying theinvention taken substantially on lines 3-3 of Figure 2;

Figure 4 is a perspective view illustrating the diffusing means used atthe base of the prismatic members illustrated in Figure 3; 30

Figure 5 is a fragmentary enlarged view similar to Figure 3 illustratinganother form of the invention;

Figure 6 is an enlarged perspective view illustrating the formation atthe base of the pris- 35 matic members shown in Figure 5;

Figure 7 is a side View of a headlamp with certain parts broken away toillustrate the direction of the light rays produced by the lamp lament;

Figure 8 is a fragmentary View of the lens shown in Figure 7diagrammatically illustrating the direction of the light rays passingthrough the base of the prismatic members;

Figure 9 is a vieW of the lens structure illus- 45 trated in Figure 8,the lens being shown tilted in the direction of the arrows of the line9-9 of Figure 8;

Figure l0 is a side View of a headlamp with parts broken away toillustrate the direction of 50 the light rays passing through anotherform of lens embodying the invention;

Figure 11 is an enlarged fragmentary View of the form of lens shown inFigure 10 diagrammatically illustrating the direction of the light 55rays passing through the base of the prismatic zones;

Figure 12 is a view of the lens structure shown in Figure 11 the Viewbeing in the direction of the arrows of the line I 2-I2 of Figure 11;

Figure 13 is a side View of a headlamp construction with parts brokenaway to illustrate the direction of light rays passing through a lensstructure of my invention;

Figure 14 is an enlarged fragmentary view of the lens shown in Figure 13diagrammatically showing the direction of light rays passing through thebase of the prismatic members on the upper portion of the lens.

Figure 15 is an enlarged fragmentary view of the lens shown in Figure 13diagrammatically showing the direction of light rays passing through thebase of the prismatic members of the lens on the lower half portion ofthe lens.

Figure 16 is a view of the lens structure illustrated in Figure 14 theview being in the direction of the arrows of the line I6-I6 of Figure14;

Figure 17 is a View of the lens structure in Figure 15 the view being inthe direction of the arrcws of the line II--I'I of Figure 15;

Figure 18 illustrates the beam projection or pattern produced by thearrangement illustrated in Figure '7, including the projected patternproduced by a lens formed without the light spreading means of theinvention;

Figure 19 illustrates the pattern of the light projected by thearrangement illustrated in Figure 10, incorporating the projectedpattern produced with a similar type of lens omitting the lightspreading means of the invention;

Figure 20 illustrates the pattern of the light projected by thearrangement illustrated in Figure 13 incorporating the projected patternproduced by a similar type of lens omitting the light controlling meansof my invention.

As a practical illustration of the invention the same is shown asincorporated on an automotive vehicle headlamp, but it is to beunderstood that I contemplate the use of the invention Where theprinciples herein described may be found to be applicable.

Referring to the drawings and particularly to Figure l, the invention isshown as embodied in a headlamp construction, particularly usable forautomotive vehicles. The headlamp comprises an cuter metallic shell i0which removably supports a lens I2 by means of a detachable rim memberIl. The headlamp casing I0 suitably supports a parallelizing reflectorI6 with which is associated a lamp bulb I8 having a suitable source oflight in the form of concentrated filament I9 located substantially atthe focal center of the reflector I6. The lens I2 comprises a disk ofglass or other suitable transparent material and is formed on its innersurface with a plurality of prisms 2B of the proper angularity withrespect to the vertical plane of the lens I2 for controlling thedirection of the light rays reflected from the source of light by thereflector and those directly emitted by filament I9. The prisms 20extend across the lens I2 forming prismatic zones, each zone having thedesired refractive power for projecting a light beam of predeterminedintensity and contour. In the form of the invention shown the prisms areformed at their inclined surface with vertical ribs for the purpose ofspreading the light passing therethrough. These ribs preferably take theform of vertical flutes 22 having the desired curvature and beingsuperimposed on the prismatic members 20 as particularly illustrated. inFigures 3 and 4 forming a unitary composite light directing means.

I provide at the base of each horizontal zone 20 or at the connectingsurface between each of the zones transition surfaces 24 of proper lightdirecting configuration for the purpose of diffusing or spreading thelight rays directed there- Yto controlling their direction in order toavoid the projection of objectionable concentrated light spcts producednormally by light rays directed to the base of the horizontal zones. Thefunction of the surfaces will be hereinafter described more in detail.In the form of the embodiment shown, the surfaces 24 are curved and madeto correspond substantially to the curvature of the vertical cylindricalribs or flutes 22. This particular arrangement aids materially in theproduction of molds of low cost for producing the accurate formation ofthe prismatic member and vertical ribs.

In order to increase the efficiency of the headlamp and for the purposeof more accurately controlling the light rays emitted from the source oflight and particularly the rays normally not reflected by the mainreflector I provide in association with the light source I9 and mainrefleeting surface i5, a supplementary reflector 25. In the form shownthe supplementary reflector 25 is suitably supported at the base of thelamp i8 by a plurality of arms or brackets 26 which hold thesupplementary reflector in proper position with respect to the focalpoint of the reflector I 6 and with respect to filament I9. Thesupplementary reflector 25 in the embodiment illustrated is of suitablecurvature or spherical contour, preferably made of metal in the form ofa segment of a sphere covering the front area of the bulb and preferablynot extending beyond a line connecting the edge of the reflector I Iiwith the center of the filament I9. The supplementary reflector 25 inthe form shown has its center of curvature on a line containing the axisof the filament I9 and the bounding limit is circular extending to suchpoints in relation to the size of the filament so that substantially allthe forwardly directed rays which normally would emerge withoutreflection are obstructed by the supplementary reflector 25 andredirected to the main reflector IB, thus the total illumination fromthe headlamp being substantially produced from reflected rays. By thearrangement shown in Figure 2 the direct rays from the filament whichwould normally project forwardly and at an angle without reflection arecut off by the supplementary reflector and directed to the mainreflector eliminating one of the causes of glare resulting from theuncontrolled direct rays emanating from the light source thus materiallyincreasing the efficiency of the headlamp.

In the modified form of the lens shown in Figures 5 and 6, the lensstructure is designed for the purpose of directing the projected lightbeam toward one side of the vehicle with which th headlamp is used,preferably the right hand side, in order to direct the light to the edgeof the road increasing the visibility of the road and materiallydecreasing glare to approaching drivers. In this form the lens includestransverse prismatic zones 2l formed with vertical half flutes 28, thelatter having the proper curvature for directing the light toward oneside of the center of the reflector, In this form of lens structure thebase of each prismatic zone 2l is formed with a plurality of surfaces 3Uof proper light refracting configuration corresponding in width to thecurvature of the half flutes 28.

I have found that due to the fact that in actual practice the source oflight is not in the form of a point located at the exact focus of theparallelizing reflector but on the contrary in all cases take the formof a filament which occupies a space considerably greater than the focusor focal center of the reflector with which the same is used, the lightrays which are produced by said source not emitting from the exact focalpoint of the reflector directed to the surfaces connecting thehorizontal light bending Zones or passing through the base of the prismsare concentrated producing light spots or beams of an intensity which ishighly objectionable. In order to avoid this difficulty I have foundafter considerable tests and experimentation that by forming theconnecting surfaces between the light bending Zones or the base of theprisms with light transition surfaces having 'the proper light directingconfiguration these objections are eliminated. I have also found that bythe incorporation of curved surfaces or surfaces of proper lightrefracting configuration at the base of the prisms included on a lensstructure I accomplish the purpose of spreading the light rays passingtherethrough and of bending certain objectionable rays downwardly thusprojecting a beam of light of less concentrated intensity over a broaderarea.

For the purpose of aiding in a better understanding of the principles ofthe invention in Figure 7 is shown a headlamp constructiondiagrammatically illustrating the direction of the light rays emanatingfrom the source and passing through the base of the prismatic memberformed in accordance with the invention. The headlamp shown includes anexterior shell 32 supporting a lens 33 preferably made of glass or othersuitable transparent material by means of a detachable rim member 35.Within the casing 32 is suitably supported a parabolic reflector 34 withwhich is associated a lamp bulb 31 having a source of light ofappreciable dimension in the form of a ccncentrated filament 36 loca-tedat the focal center of the reflectorl Adjacent to' the lamp bulb 3T andin proper spaced relation with the filament 3% is a supplementaryreflector dil. The reflector ld in the form shown is preferably made ofnontransparent material having its reflecting surface opposed to that ofthe main reflector and taking the form of a segment of a sphere. Thecenter of curvature of reflector 40 is located substantially at thecenter of filament 38, occupying an area which is bounded by a linewhich connects the central portion of the filament with the edge of thereflector, thus substantially intercepting all the direct rays emanatingfrom the source of light, redirecting the same to the reector, so that,substantially all the light emitted from the source is controlled by themain reflector.

The headlamp lens structure 33 is formed at its rear surface withprismatic Zones 35 upon the inclined rear surface are superimposed aplurality of vertical semi-cylindrical members or flutes 42 having atsurface 39, which connects said zones, a series of elements of properlight directing configuration 43 for redirecting the light rays strikingthe same. In the form shown the light directing elements 43 are of acontour having a predetermined curvature for spreading laterally therays of light to substantially the same amount to that produced by thevertical members or flutes 42.

It can be seen by examination of Figure 7 that light rays emanating fromthe filament 38 from a section located behind the focal center of thereflector identified as D will be reflected by the reflector 34 beingdirected upward from the upper half of reflector and downward from thelower half, and striking surface 39 of the primatic zone 36, will bedirected by the lens taking the direction of dotted lines R, while lightrays emanating from a section of the lament located ahead of the focalcenter of the reflector such as DI will be reflected by the reflector 3being directed downward from the upper half of the reflector and upwardfrom the lower half and in striking the base surface 3S of the prismaticZone 36 will be directed by the lens taking the direction of lines RI.Figure 8 illustrates the direction of light rays D and Dl reflected bythe upper half of the reflector, also the direction of a light ray Ewhich is directed by the reector and strikes one side of the center ofthe light directing surface 43. It should be noted that the upwardlydirected rays of light from the reflector such as D and E strike theunder surface of the glass 39 and are reflected or directed downwardlyby the optical surface of the lens as indicated by dotted lines R and S;and that the downwardly directed rays of light from the reflector suchas DI and El will pass through a surface adjacent to the edge ofinclined surface 36 and are refracted upwardly by the optical surfaceinside of the glass 39. Figure 9 shows the lateral direction of rays D,E, F as well as DI, El and FI by dotted lines R, S, T and RI', Sl and TIrespectively, which indicate the lateral spreading action of the curvesurfaces 43 at the base of each prismatic zone.

In the form of the embodiment illustrated in Figure 'l the surfaces 39connecting the light bending zones while being formed of a plurality ofmembers of curved contour have a fiat surface forming substantially 90angle with the vertical plane of the lens as particularly shown inFigure 8. The particular beam pattern projected by this arrangement isillustrated diagrammatically in Figure 18, where it can be seen that thearea A identified by cross hatching in dotted lines is formed by theprojection of the light rays passing through the surface connecting theprismatic zones provided with the curved surfaces or of proper lightdirecting contour of the invention, the intensity of the beam projectedbeing of small candlepower per square inch thus minimizing glaringcharacteristics. Figure 18 also shows that by the omission of the curvedsurface at the base of the prismatic Zones the beam projected by thelight rays striking the same produces a concentrated light spot or areaB identied by the double cross-hatching having a portion above the uppercut off or horizontal light controlling lines of the main beam. Theconcentrated light spot B having considerable intensity per square inchthus causing glare highly objectionable to observers of the headlamp.

The effect of the curved surface on the bases of a prism or in formingthe surface connecting the light bending zones to a proper lightdirecting configuration in addition to spreading the light over abroader area also increases the total effective non-objectionablecandlepower projected, by materially adding to the effectiveillumination normally produced without glare by rays emanating from thelight source, this is shown in Figure 18 where the lower portion of thebeam pattern A superimposes on or overlaps the upper portion of the mainconcentrated beam pattern produc-ed by the lament, which is indicated bythe area bound by the full lines, the hot spot produced by the filamentbeing illustrated as the area C outlined by the heavy lines.

In Figure 10 I have illustrated the application of the principles of theinvention to a headlamp construction incorporating the cooperativerelationship of the principal element of the invention included in theheadlamp construction shown in Figure '7, the form shown in Figure 10differentiating therefrom by the lens structure used. The headlampcomprising an open ended casing enclosing a parallelizing reflector 47supporting a lamp bulb 48 having a concentrated illament 50 locatedsubstantially in the region of the focus of the reflector 41. Asupplementary curved reflector 52 of suitable dimensions with respect tothe main reflector and filament 50 is so positioned in front of thefilament so as to cut off rays which will normally project forwardly.The open end of the headlamp casing 45 detachably supports a cover orlens 54 made of glass or other suitable material. rIhe lens 54 in theform shown comprises a plurality of transverse prismatic zones 55 theinclined surface of the prism being formed with semi-cylindrical members51 of a suitable curvature for spreading laterally the light passingtherethrough. The surface of the base member 58 of each prismatic zoneforming an angle of less than 90 with the vertical smooth surface of thelens 54, this angle corresponding to what is known as the draft angle ofthe mold. The angularity of the surface 58 of the base member beingparticularly shown in Figures 10 and ll. Surface 58 constituting thebase of the prismatic Zone is formed with a series of elements of properlight refracting configuration being of curved contour in the form shownand having the proper refractive lateral spreading power similar to thatof the vertical semi-cylindrical members 57 so as to form a symmetricalbeam pattern.

Figure 10 shows that light rays emanating from a portion oflament 50located behind the focus of reflector 47, such a light ray D will bereflected by reflector 41 and in striking the surface 58 which connectsthe light bending Zones will take the direction of dotted lines R, whilelight rays emanating from a portion of filament 50 located in front ofthe focus of the reflector, such as DI will be reflected and in strikingthe base or surface 58 of the prismatic zones will be directed asindicated by dotted lines Rl. Figure l1 illustrates the direction oflight rays D and DI reflected by the upper half of the reflector andalso the direction of light rays E and El which strike one side of thecenter of the light directing surfaces 58 and 58. The upwardly directedrays D and E which strike the inclined surface 58 connecting the lightbending zones, which surface is inclined with reference to thehorizontal due to the draft angle of the mould, are refracted upwardlyas these rays strike this surface at an angle which is less than theangle of total reflection, their direction being indicated by dottedlines R and S. The downwardly directed rays such as DI and El willstrike surface 58 and will be reflected downwardly as these rays form anangle with surface 58 of such value that reflection occurs.

Figure 12 illustrates the lateral refractive power of the curved surface60. The figure shows the direction taken with respect to the verticalaxis of the reflector by light rays D, E and F as Well as DI, El and Fl,the direction of the refracted rays being indicated by dotted lines R,S, T and RI, SI and Tl respectively, which show the lateral spreading ofthese rays caused by the curvature of refractive members 60 and 60',thus eliminating the projection of a light beam of concentratedintensity.

In the form of the embodiment illustrated in Figures 10 to 12 inclusive,the base 58 of the prismatic zone while being formed of a series ofmembers of curved contour has a flat surface forming an angle less than90 with the vertical plane of the lens. This angularity is particularlyshown in Figures 10 and 11.

The beam pattern projected by the arrangement shown in Figure 10 isillustrated diagrammatically in Figure 19 where it can be seen that thearea G identified by the cross-hatching in dotted lines and covering anarea outlined by the dotted lines is formed by the projection of lightrays passing through the base of the prismatic zones provided withcurved surfaces or surfaces of proper light refractive contour of theinvention. The intensity of the beam projected forming this patternbeing of small candle power per square inch diminishing the possibilityof glare.

In Figure 19 it is shown that by the omission of the curved surface ofthe invention at the base of the prismatic zone the beam projected bythe light rays passing through the base of the zone produces what isknown as a concentrated light spot area H, identified by the doublecross-hatching having a portion above the upper cut-off or horizontallight controlling line L of the main beam, as well as projecting belowthe beam pattern produced by the main beam. This concentrated light spotH is of a sufficient candle power intensity per square inch that thesame produces glare highly objectionable to approaching drivers orpedestrians. By the use of light refracting members located at the baseof the prismatic zones, this concentrated light spot H is spread,superimposing the area covered by the concentrated beam pattern producedby the filament which is indicated in Figure 19 by the area bound by thefull lines, the hot .spot produced by the filament being illustrated asthe area M outlined by heavy lines.

In the modiled form of the invention, shown in Figures 13 to 17,inclusive, the headlamp construction includes an exterior open endedcasing enclosing a parallelizing reflector 58 supporting a lamp bulb 'I0having a concentrated filament 12 located substantially in the region ofthe focus of the reflector 68. The open end of the headlamp casing B5detachably supports a cover or lens 'i4 by means of a removable rimmember 1G. The lens 'I4 in the form shown is made of glass or othersuitable transparent material having a plurality of transverse prisms18, the inclined surface of each prism being formed withsemi-cylindrical members or flutes 19 of a predetermined curvature forspreading laterally light passing therethrough. The lower surface orbase 82 of each prismatic member or zone 18 in the form shown is formedwith a series of elements of proper light refractive configuration 82 asparticularly shown in Figures 16 and 17 which in the form illustratedare of curved contour and have the proper lateral refractive power forspreading the light passing therethrough to substantially the sameamount of the spreading produced by the vertical cylindrical members 19.In the arrangement shown the supplementary reflector which has been usedin the lamp structure hereinbefore described is omitted.

Figures 13 to 15, inclusive, show diagrammatically the direction ofYlight rays emanating from portions of the filament located behind thefocus of the reflector 68 where it can be seen that a light ray such asDI and D8 which emanate from a portion of the filament I2 located behindthe focus of the reflector 68 is reected by the reflector and in passingthrough the base 80 of the prismatic Zone 'I8 will be reflected takingthe direction of dotted lines RI and R8, while the light ray emanatingfrom a portion of the filament 12 located in front of the focus of thereflector such as D3 and D6 will be reflected by the reflector 68 and inpassing through the base 86 of the respective prismatic Zones will be`reected taking the direction of dotted lines R3 and R6 shown in Figures13 to 15, inclusive, which indicatetheir direction with reference to thehorizontal. Figures 13 to 15 also indicate the direction taken by directrays not reflected by the reflector such as D2,`D4, D5 and D1 emanatingfrom sections of the lament located respectively in front of or behindthe focus of the reflector S8. These rays in passing through the basesurface 8i) of the prismatic zones will take the direction indicated bydotted lines R2, R4, R5 and R1 particularly shown in Figures 14 and 15.

'Figures 16 and 17 diagrammatically illustrate the lateral directiontaken by rays which are directed to one side of the central curvature ofthe light reflecting member 82 located at the base 8B of each prismaticZone 18. In this particular case the dotted lines illustrate thespreading action effected by the refractive elements of the inventionwith reference to the vertical axis of the reflector. In the form of theembodiment illustrated in Figures 13 to 17, inclusive, the base 80 ofthe prismatic zone while being formed of a series of members of curvedcontour has a iiat surface forming an angle of substantially 90 withrespect to the vertical plane of the lens. This angularity isparticularly shown in Figure 14.

The light beam pattern projected by the arrangement shown in Figure 13is illustrated diagrammatically in Figure 2O where it can be seen thatthe area K identified by the cross-hatching in dotted lines and coveringan area outlined by dotted lines is formed by the projection of lightrays passing through the base of the prismatic Zones or surfaces ofproper refractive light contour, the intensity of the beam patternprojected being of a small candle power per square inch diminishingthereby the possibilities of glare. In Figure 20 it is shown that by theomission of the curved surface of the invention at the base of theprismatic zones the beam projected by the light rays passing through thebase of the zones produces what is known as a concentrated light spotarea N identied by the double cross-hatching having a portion above theupper cut-off line of the main beam, which also projects light below thepattern of the main beam. This area N is of suicient candle power persquare inch to produce glare. It can be seen that by the use of thelight deflecting members of the invention this concentrated light spotarea N is Spread, forming a beam pattern covering area K whichsuperimposes the area covered by the beam pattern bounded by the fulllines produced by the filament. The hot spot produced by the filament isillustrated as the area P outlined with heavy lines. I have found thatby the incorporation of proper light deflecting means located at thebase of the prisms or at the surfaces connecting the light bending zonesconcentrated objectionable light projected which is produced by prismshaving rounded corners at the point where the inclined surfaces of theprisms join the .base of the prisms is also controlled by the spreadingaction of the light deflecting means of the invention. These roundedcorners are produced in the lens structure due to the fact that it isextremely diicult to form sharp corners at this point when the lens witha prismatic structure is moulded.

While in the embodiments shown in the invention Figures '7 to 17inclusive the lens structure includes vertical members in the form ofsemi-cylindrical members superimposed on the inclined surface of thetransverse prismatic zones it is to be understood that the inventionalso includes a lens structure wherein the flutes or cylindrical membersextend vertically across the front face of the lens structure, thetransverse prisms being formed on the rear face of the lens and its basesurface incorporating the light directing elements of the invention.

It is apparent that, within the scope of the invention, modificationsand dilferent arrangements may be made other than is h-erein disclosed,and the present disclosure is illustrative merely, the inventioncomprehending all variations thereof.

What I claim is:

l. In a headlamp, the combination of a concave reflector adapted toparallelize rays of light issuing from the source of light locatedadjacent the focus of the reflector, said source having appreciabledimensions; and a lens for the front cover, the surfaces of the lensarranged so as to form a transverse light refracting prism for bendinglight downwardly, the base of said prism being provided with a pluralityof convex spreading flutes of substantially uniform curvature locatedtransversely along the base of said prism to laterally disperse lightissuing from said headlamp due to that portion of light issuing from thesource of light outside the focus of the reflector.

2. In a headlamp, the combination of a paraboloid shaped reflectoradapted to parallelize rays of light issuing from the source of light; asource of light located adjacent the focus of the reflector, said sourcehaving appreciable dimensions; and a lens for the front cover of saidheadlamp, the surfaces of the lens arranged so as to form' a pluralityof transverse prisms for bending light downwardly, the base of eachprism being provided with a plurality of substantially uniformcylindrical spreading flutes of shallow curvature located transverselyalong the base of said prisms to laterally disperse light issuing fromsaid source of light outside the focus of the reflector and passingthro-ugh said base of said prisms.

3. A headlamp lens formed with a plurality of horizontally disposedprismatic zones for bending light rays downwardly, the bases of saidprismatic zones being slightly inclined with respect to the horizontalaxis of said lens; vertically disposed flutes associated with saidprismatic zones directing light rays laterally; a plurality of sectionsof shallow curvature formed on the base of each of said prismatic zones,said sections being in substantial alignment with the verticallydisposed flutes.

4. In a headlamp, the combination of a reflector; a source of lightlocated adjacent the focus of the reflector; a lens for the front coverof said headlamp, the surfaces of said lens formed with a plurality ofprismatic zones arranged with respect to said source of light andreflector for Cil bending light rays downwardly; vertically disposedflutes associated with said prismatic zones for directing light rayslaterally; a plurality of curved surfaces forming the baseof eachof saidprismatic zones, said curved surfaces having substantially' the samecurvature as Vthe curvature of the vertically disposed flutes.

5. In a headlamp, the combination ofY a reflector; a source cf lightassociated with said reflector; a lens for'the front cover of saidheadlanip, the surfaces of said lens formed with a plurality ofprismatic zones arranged With-respect to said light source and reflectorfor bending light rays downwardly; vertically disposed? half flutesformed on said lens and having the proper curvature for directingY lightrays toward one side of the central axis of said head- Y lamp; Vaplurality of curved surfaces forming the base of each prismaticizone,said surfaces having substantially the same amplitude of curvature asthe curvature of the vertically Ydisposed half flutes.

6. In a lens for a headlamp farmed of transparent material having afront surface and rear surface, one of said surfaces being formed with aplurality of inclined portions whereby said front and rear surfacesforming a plurality of transverse light refracting prisms forcontrolling the horizontal distribution of light rays issuing from theheadlamp; a plurality of half flutes formed on the inclined portion ofsaid lens and having the proper curvature for directing light raystoward ene side of the-*central axis of the lens; and a pluralityofspreading flutes located transversely along the base iof said prisms ofsubstantially uniform curvature to laterally disperse light passingthrough the base of said prisms.

7. In a lens for a headlamp formed of transparent material havingVV afront surface and a rear surface, one of said surfaces being formed witha plurality of inclined portions whereby said front and rear surfacesferm a plurality of transverse prismatic light refracting Zones; aplurality of cylindrical flutes formed on and located transversely alongthe inclined surface portions of said lens; and a plurality of spreadingflutes located transversely along the base of saidiprismatic zones tolaterally disperse light passing through therbase of said refractingzones.

8. In a lens for a headlamp formed of glass having a front surface and aplurality of inclined portions on the rear'surface Vforming a pluralityof transverse light refracting prisms for controlling the horizontaldistribution of light issuing from the headlamp; a plurality of flutesformed-on the inclined portions of said Vlens for controlling thelateral distribution of light issuing from the headlamp.; and aplurality kof spreading flutes located transversely along the base ofsaid prisms of substantially shallow curyature to laterally disperselight passing therethrough.

.i CHARLES E. GODLEY.

